RESUMO
BACKGROUND: To compare dentoskeletal changes produced by the maxillary splint headgear and cervical headgear appliance during the early phase of Class II treatment, specially the initial overjet and upper incisors position. SUBJECTS AND METHODS: In this retrospective study, 28 Class II patients treated with the maxillary splint headgear (MSG, mean age 10.1 ± 1.9 years) and 28 Class II patients treated with cervical headgear (CHG, mean age 9.5 ± 1.9 years) were evaluated before and after treatment. Statistical comparisons between the two groups for cephalometric measurements at T1 and for T2-T1 changes were performed by means of independent sample t tests. RESULTS: The MSG showed a significantly greater reduction of the overjet in comparison to the CHG (- 2.4 mm and - 0.7 mm, respectively) and a significantly greater maxillary incisor uprighting (- 1.8 mm and 0.4 mm, respectively). In the MSG, overjet correction was due mainly to mandibular advancement (3.5 mm), while the correction of molar relationship (3.9 mm) was 64% skeletal and 36% dentoalveolar. In the CHG, the overjet correction was also more skeletal, due to mandibular growth (1.8 mm), while correction of molar relationship (3.5 mm) was 63% dentoalveolar and 37% skeletal. CONCLUSIONS: Both groups showed favorable skeletal mandibular changes, which was more significant in the MSG. Regarding tooth movement, the maxillary splint headgear was more effective in uprighting upper incisors and reducing the overjet than cervical headgear appliance.
Assuntos
Aparelhos de Tração Extrabucal , Má Oclusão Classe II de Angle , Cefalometria , Criança , Humanos , Maxila , Estudos Retrospectivos , Contenções , Técnicas de Movimentação DentáriaRESUMO
INTRODUCTION: This study aimed to determine the volumetric effects on the upper airways of growing patients with Class II malocclusion treated with the Herbst appliance (HA). METHODS: Volumetric measurements of the upper airways of 42 skeletal Class II malocclusion patients (mean age: 13.8 ± 1.2 years; ranging from 12.0 to 16.9 years) were assessed using cone-beam computed tomography scans acquired before treatment (T0) and approximately 1 year later (T1). The sample comprised a Herbst appliance group (HA group [HAG]; n = 24), and a comparison group (comparison group [CG]; n = 18) of orthodontic patients who had received dental treatments other than mandibular advancement with dentofacial orthopedics. RESULTS: In CG, nasopharynx and oropharynx volumes decreased slightly during the observation period (9% and 3%, respectively), whereas the nasal cavity volume increased significantly (12%; P = 0.046). In HAG, there was an increase in the volume of all regions (nasal cavity, 5.5%; nasopharynx, 11.7%; and oropharynx, 29.7%). However, only the oropharynx showed a statistically significant increase (P = 0.003), presenting significant volumetric changes along the time (T1-T0) in HAG. CONCLUSION: Mandibular advancement with the HA significantly increased the volume of the oropharynx, but no significant volumetric modifications were observed in the nasal cavity and nasopharynx.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Adolescente , Cefalometria , Criança , Humanos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/terapia , Mandíbula , Avanço Mandibular , OrofaringeRESUMO
AIM: To develop and validate a prediction model to forecast long-term stability of early treatment with rapid maxillary expansion (RME) and facemask (FM) in a large sample of Class III growing patients. METHODS: The Brazilian Group (BG) consisted of 73 consecutively treated Caucasian Class III patients (41 females and 32 males). Mean age at T0 (before treatment) was 7.1 ± 1.6 years, while mean age at T1 (long-term follow-up) was 21.8 ± 3.2 years. The Italian Group (IG, validation cohort) comprised 28 consecutively treated Caucasian Class III patients (14 females and 14 males, mean age at T0 9.0 ± 1.3 years and mean age at T1 18.2 ± 1.4 years). Cephalometric analysis was performed on lateral cephalograms at T0. Gender and cephalometric variables, chronologic age, and dentition phase at T0 were used as predictors for long-term unsuccessful treatment at T1. All predictors for unsuccessful treatment in the BG were subjected to bivariate logistic regression. Only those statistically significant predictors in the bivariate logistic regression entered mixed stepwise logistic regression with P = 0.05 to enter and to leave. The validity of the prediction model derived from the BG was then tested on the IG. RESULTS: The prediction model consisted of only one cephalometric variable: the angle between the Condylar Axis and the Mandibular Plane (CondAx-MP) (odds ratio: 1.52, 95% confidence interval: 1.25-1.85, P < 0.0001). Unsuccessful treatment at T1 was predicted for values of CondAx-MP at T0 greater than the cut-off value of 147.8 degrees. BG patients predicted incorrectly were 3 out of 22 for the unsuccessful cases and 1 out of 51 for the successful cases. Therefore, accuracy was 0.95, sensitivity 0.86, specificity 0.98, and positive and negative predictive values were 0.95 and 0.94. When the predictive model was applied on IG, all five unsuccessful cases were predicted correctly, while only 1 out of 23 successful patients was predicted incorrectly. CONCLUSION: CondAx-ML was identified as a reliable predictor for long-term stability of early Class III treatment with RME and FM.
Assuntos
Má Oclusão Classe III de Angle/diagnóstico por imagem , Má Oclusão Classe III de Angle/terapia , Maxila , Adolescente , Adulto , Idoso de 80 Anos ou mais , Brasil , Cefalometria , Criança , Pré-Escolar , Aparelhos de Tração Extrabucal , Feminino , Humanos , Masculino , Técnica de Expansão Palatina , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVES: To perform a three-dimensional evaluation of the position of the condyles in patients treated with Herbst appliance (HA) in two stages of cervical vertebral maturation. SETTING AND SAMPLE POPULATION: Retrospective case-control study. Pubertal Herbst group (PHG; n = 24, mean age 14.5 years, CS 3 and CS 4) and pre-pubertal Herbst group (PPHG; n = 17, mean age 9.9 years, CS 1 and CS 2) were contrasted with comparison groups of non-orthopaedically treated Class II patients in pubertal (PCG; n = 17, mean age 13.9 years) and pre-pubertal maturational stages (PPCG; n = 18, mean age 10.6 years). MATERIALS AND METHODS: Cone-beam computer tomography scans were taken before treatment (T0) and at T1 after 8 to 12 months. Point-to-point measurements of the displacement of the condyles between T0 and T1, relative to the glenoid fossae, were performed in the X, Y, Z and 3D perspectives. Qualitative assessments using semi-transparent overlays and colour mapping also were produced. RESULTS: The displacement of the condyles within the glenoid fossae in the treated groups was small (<0.75 mm; P > .05). Relative to the glenoid fossa, condylar position at T1 was similar to T0 in pre-pubertal and pubertal groups (P > .05). Similar condylar rotations from T0 to T1 were observed in Herbst and comparison groups, and no significant difference was found between pre-pubertal and pubertal patients. CONCLUSIONS: Regardless the stage of skeletal maturation, HA treatment did not change the condyle-glenoid fossa relationship.
Assuntos
Cavidade Glenoide , Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Adolescente , Estudos de Casos e Controles , Criança , Humanos , Côndilo Mandibular , Estudos Retrospectivos , Articulação TemporomandibularRESUMO
OBJECTIVES: The aim of this study was to compare the reproducibility of skeletal maturation assessments by raters with similar orthodontic experience using hand-wrist (HW) and cervical vertebral maturation (CVM) methods. METHODS: HW and lateral cephalometric radiographs from 15 subjects (8 males and 7 females; ages, 9-16 years) were selected randomly. HW skeletal maturation was evaluated by the method of Greulich and Pyle, and CVM staging was evaluated by the method of Baccetti et al. Six orthodontic residents evaluated all images at three time periods: T1, initial evaluation; T2, re-evaluation after 7 days and T3, final evaluation after 5 weeks. Intra- and interexaminer reproducibility was evaluated with the intraclass correlation coefficient; the limits of agreement (LoA) were determined by using the Bland-Altman method. RESULTS: The intraexaminer reliability assessed by intraclass correlation coefficient was scored as good for both of methods (T1-T2-T3 HW = 0.89 and CVM = 0.80; T1-T2 HW = 0.87 and CVM = 0.77; T2-T3 HW0 = 0.90 and CVM = 0.81), as well as the interexaminer evaluation, with the exception of HW-T1, which scored excellent (0.92). The width of LoA from Bland-Altman plot of cervical vertebra method was narrower (CVM T1-T2: -2.3 and +1.8; CVM T2-T3: -2.0 and +2.0) than the HW method (HW T1-T2: -3.9 and +4.8; HW T2-T3: -4.0 and +3.5). CONCLUSIONS: Both HW and CVM methods presented good reproducibility for intra- and interexaminer correlation assessments. The small LoA indicated that the CVM is a reproducible method.
Assuntos
Determinação da Idade pelo Esqueleto/métodos , Cefalometria/métodos , Vértebras Cervicais/diagnóstico por imagem , Mãos/diagnóstico por imagem , Punho/diagnóstico por imagem , Adolescente , Criança , Feminino , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
ABSTRACT Rapid maxillary expansion (RME) primarily involves the mechanical opening of the midpalatal suture of the maxillary and palatine bones. The fusion of the midpalatal suture determines the failure of RME, a common event in late adolescents and young adults. Recently, the assessment of the maturation of midpalatal suture as viewed using cone beam computed tomography (CBCT) has been introduced. Five maturational stages of the midpalatal suture have been presented: Stage A = straight high-density sutural line, with no or little interdigitation; Stage B = scalloped appearance of the high-density sutural line; Stage C = two parallel, scalloped, high-density lines that lie close to each other, separated in some areas by small low-density spaces; Stage D = fusion of the palatine bone where no evidence of a suture is present; and Stage E = complete fusion that extends also anteriorly in the maxilla. At Stage C, less skeletal response would be expected than at Stages A and B, as there are many bony bridges along the suture. For patients at Stages D and E, surgically assisted RME would be necessary, as the fusion of the midpalatal suture already has occurred either partially or totally. This diagnostic method can be used to estimate the prognosis of the RME, mainly for late adolescents and young adults for whom this procedure is unpredictable clinically.
RESUMO A expansão rápida da maxila (ERM) essencialmente consiste na abertura mecânica da sutura palatina mediana tanto nos ossos maxilares quanto nos ossos palatinos. A fusão da sutura palatina mediana determina o insucesso da ERM, um evento comum na adolescência tardia e fase adulta jovem. Recentemente, propôs-se a avaliação da maturação da sutura palatina mediana em tomografias computadorizadas de feixe cônico (TCFC), sendo apresentados cinco estágios maturacionais: Estágio A = linha sutural de alta densidade retilínea, sem ou com suave interdigitação; Estágio B = linha sutural de alta densidade, com aspecto tortuoso; Estágio C = duas linhas de alta densidade, paralelas e curvilíneas, que se aproximam em algumas regiões e, em outras, são separadas por espaços de baixa densidade; Estágio D = a fusão ocorreu no osso palatino, onde não há evidência de sutura; e Estágio E = fusão completa, que se estende anteriormente na maxila. No Estágio C, esperam-se menores efeitos esqueléticos da ERM, comparado aos Estágios A e B, visto que há muitas pontes ósseas ao longo da sutura. Para pacientes nos Estágios D e E, a expansão rápida da maxila assistida cirurgicamente (ERMAC) seria necessária, já que a fusão da sutura palatina mediana ocorreu parcial ou totalmente. Esse método de diagnóstico pode ser utilizado para estimar o prognóstico da ERM, principalmente na adolescência tardia e fase adulta jovem, período em que esse procedimento ainda apresenta-se imprevisível clinicamente.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Palato/diagnóstico por imagem , Técnica de Expansão Palatina , Tomografia Computadorizada de Feixe Cônico/métodos , Palato/cirurgia , Braquetes Ortodônticos , Suturas Cranianas/diagnóstico por imagemRESUMO
INTRODUCTION: The aim was to evaluate three regions of reference (Björk, Modified Björk and mandibular Body) for mandibular registration testing them in a patients' CBCT sample. METHODS: Mandibular 3D volumetric label maps were built from CBCTs taken before (T1) and after treatment (T2) in a sample of 16 growing subjects and labeled with eight landmarks. Registrations of T1 and T2 images relative to the different regions of reference were performed, and 3D surface models were generated. Seven mandibular dimensions were measured separately for each time-point (T1 and T2) in relation to a stable reference structure (lingual cortical of symphysis), and the T2-T1 differences were calculated. These differences were compared to differences measured between the superimposed T2 (generated from different regions of reference: Björk, Modified Björk and Mandibular Body) over T1 surface models. ICC and the Bland-Altman method tested the agreement of the changes obtained by nonsuperimposition measurements from the patients' sample, and changes between the overlapped surfaces after registration using the different regions of reference. RESULTS: The Björk region of reference (or mask) did work properly only in 2 of 16 patients. Evaluating the two other masks (Modified Björk and Mandibular body) on patients' scans registration, the concordance and agreement of the changes obtained from superimpositions (registered T2 over T1) compared to results obtained from non superimposed T1 and T2 separately, indicated that Mandibular Body mask displayed more consistent results. CONCLUSIONS: The mandibular body mask (mandible without teeth, alveolar bone, rami and condyles) is a reliable reference for 3D regional registration.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Imageamento Tridimensional , Mandíbula/diagnóstico por imagem , Radiografia Dentária , Adolescente , Criança , Humanos , Modelos Anatômicos , Valores de ReferênciaRESUMO
Rapid maxillary expansion (RME) primarily involves the mechanical opening of the midpalatal suture of the maxillary and palatine bones. The fusion of the midpalatal suture determines the failure of RME, a common event in late adolescents and young adults. Recently, the assessment of the maturation of midpalatal suture as viewed using cone beam computed tomography (CBCT) has been introduced. Five maturational stages of the midpalatal suture have been presented: Stage A = straight high-density sutural line, with no or little interdigitation; Stage B = scalloped appearance of the high-density sutural line; Stage C = two parallel, scalloped, high-density lines that lie close to each other, separated in some areas by small low-density spaces; Stage D = fusion of the palatine bone where no evidence of a suture is present; and Stage E = complete fusion that extends also anteriorly in the maxilla. At Stage C, less skeletal response would be expected than at Stages A and B, as there are many bony bridges along the suture. For patients at Stages D and E, surgically assisted RME would be necessary, as the fusion of the midpalatal suture already has occurred either partially or totally. This diagnostic method can be used to estimate the prognosis of the RME, mainly for late adolescents and young adults for whom this procedure is unpredictable clinically.
Assuntos
Tomografia Computadorizada de Feixe Cônico , Técnica de Expansão Palatina , Palato/diagnóstico por imagem , Adolescente , Tomografia Computadorizada de Feixe Cônico/métodos , Suturas Cranianas/diagnóstico por imagem , Feminino , Humanos , Masculino , Braquetes Ortodônticos , Palato/cirurgia , Adulto JovemRESUMO
OBJECTIVE: To test the following two hypotheses regarding the consequences of Herbst appliance (HA) insertion: 1) a significant clockwise mandibular rotation will occur and 2) the displacement of the condyles will follow the same magnitude of the changes of overjet (OJ) and overbite (OB). METHODS: Virtual 3D surface models of 25 patients were generated from cone-beam computed tomographs taken before treatment and immediately after HA insertion. Scans were registered on the cranial base and were analyzed using point-to-point measurements, color-coded maps, and semitransparent overlays. Statistical tests included correlation and simple regression analysis. RESULTS: Pitch rotation, ranging from -2.2° to 2.2° (mean, 0.2°), was observed in clockwise and counterclockwise directions. Condylar sagittal displacement presented a positive correlation with OJ changes. Each millimeter of OJ correction resulted in an anterior condylar displacement of approximately 0.95 mm. Vertical condylar displacement correlated with OB changes and varied mostly between 2 mm and 4.5 mm. CONCLUSION: Immediately after HA insertion, no significant clockwise mandibular rotation was observed. The condyles were displaced anteriorly and inferiorly. Condylar anterior displacement and OJ correction presented a ratio close to 1:1. The vertical displacement of the condyles did not follow the same magnitude of OB changes.
RESUMO
Introduction: The adequate indications for the timing of treatment for Class II malocclusion are mandatory for the ethical and efficient practice of orthodontics, but clinicians are reluctant to accept new information that contradicts their preferred method of treatment. Objective: The aim of this investigation was to assess the agreement regarding the indications for Class II malocclusion interceptive therapy between a group of international opinion-makers on early treatment and a group of orthodontists and to compare their treatment indications with the current evidence-based knowledge. Material and method: An electronic survey containing photographs of mild, moderate and severe Class II malocclusions in children was sent to two panels of experts. Panel 1 (n=28) was composed of international orthodontists who had authored world-class publications on early orthodontic treatment, and Panel 2 (n=261) was composed of clinical orthodontists. Based on a 5-point Likert-type scale, the orthodontists selected their therapy option for each of the 9 Class II malocclusion cases. Result: The Class II malocclusion treatment recommendations of Panel 2 were significantly different from those offered by Panel 1 with a skew of at least 1 scale point toward earlier treatment. The Class II malocclusion treatment recommendations of the members of Panel 1 members were in accordance with contemporary evidence-based knowledge. Conclusion: Class II malocclusion overtreatment appears to be the tendency among clinical orthodontists but not among orthodontists who are academically involved with early treatment. There is a gap between the scientific knowledge and the practices of orthodontists.
Introdução: A indicação correta da época de tratamento de uma má oclusão de Classe II é essencial para o exercício ético e eficiente da Ortodontia, mas os clínicos são resistentes em aceitar novos conceitos que contradizem seus métodos preferidos de tratamento. Objetivo: Avaliar a concordância na indicação de tratamento interceptor das más oclusões de Classe II entre um grupo de formadores de opinião em nível internacional e um grupo de ortodontistas clínicos, e comparar a indicação de tratamento com os conceitos científicos contemporâneos. Material e método: Um questionário eletrônico composto por fotografias representativas de diversos graus de gravidade no acometimento da má oclusão de Classe II em crianças foi enviado a dois painéis de especialistas. Painel 1 (n=28) foi composto por ortodontistas internacionais autores de artigos científicos em revistas de elevado impacto, e o Painel 2 (n=261) foi composto por ortodontistas clínicos. Baseando-se em uma escala de Likert de 5 pontos, os ortodontistas indicaram suas opções de tratamento para cada um dos 9 casos apresentados. Resultado: As indicações de tratamento do Painel 2 foram estatisticamente diferentes daquelas ofertadas pelo Painel 1, com pelo menos 1 ponto de divergência no sentido de tratamento mais precoce. A indicação de tratamento ortodôntico interceptor do Painel 1 está de acordo com os conceitos científicos atuais. Conclusão: Tratamento muito precoce parece ser a tendência de conduta entre os ortodontistas clínicos, mas não entre os ortodontistas que estão academicamente envolvidos com a interceptação ortodôntica. Existe uma lacuna entre o conhecimento científico e a prática da Ortodontia.
Assuntos
Ortodontia , Terapêutica , Inquéritos e Questionários , Odontólogos , Índice de Necessidade de Tratamento Ortodôntico , Má Oclusão Classe II de AngleRESUMO
OBJECTIVE: To evaluate the long-term effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis). MATERIALS AND METHODS: Twenty-three Class II patients (8 male, 15 female) were treated consecutively with the Balters bionator (bionator group). The sample was evaluated at T0, start of treatment; T1, end of bionator therapy; and T2, long-term observation (including fixed appliances). Mean age at the start of treatment was 10 years 2 months (T0); at posttreatment, 12 years 3 months (T1); and at long-term follow-up, 18 years 2 months (T2). The control group consisted of 22 subjects (11 male, 11 female) with untreated Class II malocclusion. Lateral cephalograms were analyzed at the three time points for all groups. TPS analysis evaluated statistical differences (permutation tests) in the craniofacial shape and size between the bionator and control groups. RESULTS: TPS analysis showed that treatment with the bionator is able to produce favorable mandibular shape changes (forward and downward displacement) that contribute significantly to the correction of the Class II dentoskeletal imbalance. These results are maintained at a long-term observation after completion of growth. The control group showed no statistically significant differences in the correction of Class II malocclusion. CONCLUSIONS: This study suggests that bionator treatment of Class II malocclusion produces favorable results over the long term with a combination of skeletal and dentoalveolar shape changes.
Assuntos
Aparelhos Ativadores , Cefalometria/métodos , Má Oclusão Classe II de Angle/terapia , Ortodontia Corretiva/métodos , Retrognatismo/terapia , Feminino , Humanos , Masculino , Ortodontia Corretiva/instrumentaçãoRESUMO
AIM: To examine the long-term effects induced by treatment with the function regulator (FR-2) appliance 7 years post-treatment compared with untreated class II subjects. SUBJECTS AND METHODS: The FR-2 sample was collected prospectively and comprised 17 subjects (10 boys and 7 girls, mean age 10.8 years) who were treated with the FR-2 appliance for 1.7 years and re-evaluated 7.1 years after treatment. The step-by-step mandibular advancement was performed gradually (increments up to 3-4 mm), until a 'super class I' molar relationship was obtained. The control group consisted of 17 class II subjects (9 boys and 8 girls, mean age 11.3 years) with class II malocclusion, excessive overjet, and class II molar relationship, matched to the treated group as to ages at all times, gender distribution, and stages of skeletal maturity (evaluated by the cervical vertebral maturation method). The lateral cephalograms were analysed at T1 (initial), T2 (final), and T3 (7.1 years post-treatment). The compatibility between the groups and the comparisons of their changes at T1-T2, T2-T3, and T1-T3 intervals were examined by independent sample t-tests (P < 0.05). RESULTS: FR-2 treatment provided a significant improvement in the maxillomandibular relationship due to an increase in mandibular length compared with controls, which remained stable over time. Also overjet, overbite, and molar relationship corrections demonstrated stability. Among dentoalveolar changes, only the increased mesial movement of the mandibular molars in the FR-2 group demonstrated stability. CONCLUSIONS: Correction of class II malocclusion remained stable 7 years after FR-2 treatment mainly due to the stability of the skeletal changes.
Assuntos
Má Oclusão Classe II de Angle/terapia , Avanço Mandibular/instrumentação , Aparelhos Ortodônticos Funcionais , Adolescente , Cefalometria/métodos , Criança , Feminino , Seguimentos , Humanos , Masculino , Má Oclusão Classe II de Angle/patologia , Má Oclusão Classe II de Angle/fisiopatologia , Mandíbula/crescimento & desenvolvimento , Avanço Mandibular/métodos , Desenvolvimento Maxilofacial/fisiologia , Dente Molar/patologia , Sobremordida/terapia , Estudos ProspectivosRESUMO
INTRODUCTION: Our objectives in this study were to evaluate in 3 dimensions the growth and treatment effects on the midface and the maxillary dentition produced by facemask therapy in association with rapid maxillary expansion (RME/FM) compared with bone-anchored maxillary protraction (BAMP). METHODS: Forty-six patients with Class III malocclusion were treated with either RME/FM (n = 21) or BAMP (n = 25). Three-dimensional models generated from cone-beam computed tomographic scans, taken before and after approximately 1 year of treatment, were registered on the anterior cranial base and measured using color-coded maps and semitransparent overlays. RESULTS: The skeletal changes in the maxilla and the right and left zygomas were on average 2.6 mm in the RME/FM group and 3.7 mm in the BAMP group; these were different statistically. Seven RME/FM patients and 4 BAMP patients had a predominantly vertical displacement of the maxilla. The dental changes at the maxillary incisors were on average 3.2 mm in the RME/FM group and 4.3 mm in the BAMP group. Ten RME/FM patients had greater dental compensations than skeletal changes. CONCLUSIONS: This 3-dimensional study shows that orthopedic changes can be obtained with both RME/FM and BAMP treatments, with protraction of the maxilla and the zygomas. Approximately half of the RME/FM patients had greater dental than skeletal changes, and a third of the RME/FM compared with 17% of the BAMP patients had a predominantly vertical maxillary displacement.
Assuntos
Aparelhos de Tração Extrabucal , Imageamento Tridimensional/métodos , Maxila/crescimento & desenvolvimento , Procedimentos de Ancoragem Ortodôntica/instrumentação , Desenho de Aparelho Ortodôntico , Técnica de Expansão Palatina , Adolescente , Cefalometria/métodos , Criança , Tomografia Computadorizada de Feixe Cônico/métodos , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Incisivo/diagnóstico por imagem , Incisivo/patologia , Masculino , Má Oclusão Classe III de Angle/terapia , Maxila/diagnóstico por imagem , Maxila/patologia , Técnicas de Movimentação Dentária/instrumentação , Técnicas de Movimentação Dentária/métodos , Dimensão Vertical , Zigoma/diagnóstico por imagem , Zigoma/crescimento & desenvolvimento , Zigoma/patologiaRESUMO
OBJECTIVE: To investigate the effects of the standard (Class II) Balters bionator in growing patients with Class II malocclusion with mandibular retrusion by using morphometrics (thin-plate spline [TPS] analysis). MATERIALS AND METHODS: Thirty-one Class II patients (17 male and 14 female) were treated with the Balters bionator (bionator group). Mean age at the start of treatment (T0) was 10.3 years, while it was 13 years at the end of treatment (T1). Mean treatment time was 2 years and 2 months. The control group consisted of 22 subjects (14 male and 8 female) with untreated Class II malocclusion. Mean age at T0 was 10.2 years, while it was 12.2 years at T1. The observation period lasted 2 years on average. TPS analysis evaluated statistical (permutation tests) differences in the craniofacial shape and size between the bionator and control groups. RESULTS: Through TPS analysis (deformation grids) the bionator group showed significant shape changes in the mandible that could be described as a mandibular forward and downward displacement. The control group showed no statistically significant differences in the correction of Class II malocclusion. CONCLUSIONS: Bionator appliance is able to induce significant mandibular shape changes that lead to the correction of Class II dentoskeletal disharmony.
Assuntos
Cefalometria/métodos , Má Oclusão Classe II de Angle/terapia , Desenvolvimento Maxilofacial/fisiologia , Ortodontia Corretiva/instrumentação , Retrognatismo/terapia , Aparelhos Ativadores , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , SoftwareAssuntos
Má Oclusão Classe III de Angle/cirurgia , Mandíbula/cirurgia , Procedimentos Cirúrgicos Ortognáticos/métodos , Osteotomia de Le Fort , Fatores Etários , Cefalometria , Criança , Queixo/cirurgia , Feminino , Humanos , Côndilo Mandibular/cirurgia , Ortodontia Corretiva , Cuidados Pré-OperatóriosRESUMO
The aim of the present investigation was to provide information about the long-term effects and optimal timing for class-II treatment with the Bionator appliance. Lateral cephalograms of 23 class-II patients treated with the Bionator were analyzed at three time periods: T1, start of treatment; T2, end of Bionator therapy; and T3, long-term observation (after completion of growth). T3 includes a phase with fixed appliances. The treated sample was divided into two groups according to their skeletal maturity as evaluated by the cervical vertebral maturation (CVM) method. The early-treated group (13 subjects) initiated treatment before the peak in mandibular growth, which occurred after completion of Bionator therapy. The late-treated group (10 subjects) received Bionator treatment during the peak. The T1-T2, T2-T3, and T1-T3 changes in the treated groups were compared with changes in control groups of untreated class-II subjects by nonparametric statistics (P < .05). The findings of the present study on Bionator therapy followed by fixed appliances indicate that this treatment protocol is more effective and stable when it is performed during the pubertal growth spurt. Optimal timing to start treatment with the Bionator is when a concavity appears at the lower borders of the second and the third cervical vertebrae (CVMS II). In the long-term, the amount of significant supplementary elongation of the mandible in subjects treated during the pubertal peak is 5.1 mm more than in the controls, and it is associated with a backward direction of condylar growth. Significant increments in mandibular ramus height also were recorded.